Two years after Mark Sanford left the South Carolina governor's office tarred by an adultery scandal, he completes an unlikely comeback to win a special congressional election.

WASHINGTON — Two years after Mark Sanford left the South Carolina governor’s office tarred by an adultery scandal, he has completed an unlikely political comeback to win a special congressional election. Sanford defeated Democratic neophyte Elizabeth Colbert Busch, sister of late-night satirist Stephen Colbert, in the Republican-leaning 1st District. He reclaims a House seat he once held for three terms.

The bitter race had been expected to be tight, but the Associated Press called it for Sanford about 8:30 p.m. — 90 minutes after the polls closed.

The Charleston-based seat, which spans five counties along the coast, is considered reliably Republican. Mitt Romney carried the district by 18 points over Barack Obama in 2012.

But national Democrats made a serious play for the seat after Sanford emerged as the Republican nominee. The national GOP all but abandoned Sanford, who at one point was considered a possible presidential hopeful before he admitted cheating on his wife with an Argentine mistress whom he called his "soul mate."

The affair came to light in 2009 when the governor vanished from public view. His staff told questioners he was hiking the Appalachian Trail alone, when in fact he was in Argentina with his mistress. That personal and professional debacle led to Sanford’s divorce.

The scandal flared up during the House campaign when his ex-wife, Jenny Sanford, accused him of violating their divorce agreement by trespassing in her house. He is to appear in court Thursday to answer her complaint.

While still in the governor’s office, Sanford was censured by his state's Republican Legislature and paid fines for misusing government resources in connection with his affair. He rebuffed calls to resign, however, and served out his second term.

His political career appeared to be finished — until Sen. Jim DeMint’s surprise resignation from the Senate last December. Tim Scott, who represented the 1st District, was appointed to replace DeMint, opening up Scott's House seat. Amid a crowded field of primary candidates, Sanford’s high name recognition — warts and all — powered him over lesser-known Republican hopefuls.

When Sanford wasn’t working to address voters' concerns about his personal foibles, he was pointing to his record as a fiscal hawk while he was a congressman and governor. He also argued that a vote for Colbert Busch would be a vote for the agenda of House Democratic leader Nancy Pelosi. He debated a cardboard cutout of the San Francisco Democrat at one stop in the final weeks.

Given the unique circumstances of the race, neither party was prepared to tout a favorable result as a potential indicator of national political trends. In fact, strategists on each side saw a potential benefit in losing.

For Republicans, a win by Colbert Busch would have ensured that a different Republican candidate would be on the ballot in 2014 in already favorable terrain, while Democrats would be forced to spend heavily to protect the seat.

Democrats, while playing hard for a win, saw a potential upside in seeing Sanford join a fractious Republican majority, replacing the lone African American Republican in the House as the national GOP struggles to regain its footing with women and minorities.

"The only thing that Democrats could get from losing is a sense of schadenfreude," said Amy Walter, national political analyst for the nonpartisan Cook Political Report. "They know that he is going to be a big thorn in the side of the Republican leadership."

The chairman of the Democratic Congressional Campaign Committee, Steve Israel, seized on that sentiment after Sanford’s victory.

"House Republicans' outreach to women voters now has Mark Sanford as the face," Israel said. "Republicans now have to defend him and stand with him until election day."

Israel's Republican counterpart, Rep. Greg Walden (R-Ore.), congratulated Sanford, adding: "These results demonstrate just how devastating the policies of Barack Obama and Nancy Pelosi are for House Democrats in 2014."